package cn.itcast.hotel.service.impl;


import cn.itcast.hotel.mapper.HotelMapper;
import cn.itcast.hotel.pojo.Hotel;
import cn.itcast.hotel.pojo.HotelDoc;
import cn.itcast.hotel.pojo.PageResult;
import cn.itcast.hotel.pojo.RequestParams;
import cn.itcast.hotel.service.IHotelService;
import com.alibaba.fastjson.JSON;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.apache.commons.lang3.StringUtils;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.common.unit.DistanceUnit;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.functionscore.FunctionScoreQueryBuilder;
import org.elasticsearch.index.query.functionscore.ScoreFunctionBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.Aggregation;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service
public class HotelService extends ServiceImpl<HotelMapper, Hotel> implements IHotelService {

    @Autowired
    private RestHighLevelClient client;

    @Override
    public PageResult search(RequestParams params) throws IOException {

        Integer page = params.getPage();
        Integer size = params.getSize();
        //1.创建请求语义对象
        SearchRequest request = new SearchRequest("hotel");
        // 调用方法,封装请求的DSL语句
        buildBasicQuery(params, request);

        // 分页查询
        Integer index = (page - 1) * size;
        request.source().from(index).size(size);

        String location = params.getLocation();
        if (location != null && !location.equals("")) {
            request.source().sort(SortBuilders
                    .geoDistanceSort("location", new GeoPoint(location))
                    .order(SortOrder.ASC)
                    .unit(DistanceUnit.KILOMETERS)
            );
        }

        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        return handleResponse(response);
    }

    @Override
    public Map<String, List<String>> getFilter(RequestParams params) {
        try {
            // 1.准备Request
            SearchRequest request = new SearchRequest("hotel");
            // 2.准备DSL
            // 2.1.query
            buildBasicQuery(params, request);
            // 2.2.设置size
            request.source().size(0);
            // 2.3.聚合
            buildAggregation(request);
            // 3.发出请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            // 4.解析结果
            Map<String, List<String>> result = new HashMap<>();
            Aggregations aggregations = response.getAggregations();
            // 4.1.根据品牌名称，获取品牌结果
            List<String> brandList = getAggByName(aggregations, "brandAgg");
            result.put("brand", brandList);
            // 4.2.根据品牌名称，获取品牌结果
            List<String> cityList = getAggByName(aggregations, "cityAgg");
            result.put("city", cityList);
            // 4.3.根据品牌名称，获取品牌结果
            List<String> starList = getAggByName(aggregations, "starAgg");
            result.put("starName", starList);

            return result;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public List<String> suggestion(String key) {
        try {
            // 1.准备Request
            SearchRequest request = new SearchRequest("hotel");
            // 2.准备DSL
            request.source().suggest(new SuggestBuilder().addSuggestion(
                    "suggestions",
                    SuggestBuilders.completionSuggestion("suggestion")
                            .prefix(key)
                            .skipDuplicates(true)
                            .size(10)
            ));
            // 3.发起请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            // 4.解析结果
            Suggest suggest = response.getSuggest();
            // 4.1.根据补全查询名称，获取补全结果
            CompletionSuggestion suggestions = suggest.getSuggestion("suggestions");
            // 4.2.获取options
            List<CompletionSuggestion.Entry.Option> options = suggestions.getOptions();
            // 4.3.遍历
            List<String> list = new ArrayList<>(options.size());
            for (CompletionSuggestion.Entry.Option option : options) {
                String text = option.getText().toString();
                list.add(text);
            }
            return list;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void deleteById(Long id) {
        try {
            // 1.准备Request
            DeleteRequest request = new DeleteRequest("hotel", id.toString());
            // 2.发送请求
            client.delete(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void insertById(Long id) {
        try {
            // 0.根据id查询酒店数据
            Hotel hotel = getById(id);
            // 转换为文档类型
            HotelDoc hotelDoc = new HotelDoc(hotel);
            // 1.准备Request对象
            IndexRequest request = new IndexRequest("hotel").id(hotel.getId().toString());
            // 2.准备Json文档
            request.source(JSON.toJSONString(hotelDoc), XContentType.JSON);
            // 3.发送请求
            client.index(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private List<String> getAggByName(Aggregations aggregations, String brandAgg) {
        // 4.1.根据聚合名称获取聚合结果
        Terms brandTerms = aggregations.get(brandAgg);
        // 4.2.获取buckets
        List<? extends Terms.Bucket> buckets = brandTerms.getBuckets();
        // 4.3.遍历
        List<String> brandList = new ArrayList<>();
        for (Terms.Bucket bucket : buckets) {
            // 4.4.获取key
            String key = bucket.getKeyAsString();
            brandList.add(key);
        }
        return brandList;
    }

    private void buildAggregation(SearchRequest request) {
        request.source().aggregation(AggregationBuilders
                .terms("brandAgg")
                .field("brand")
                .size(100)
        );
        request.source().aggregation(AggregationBuilders
                .terms("cityAgg")
                .field("city")
                .size(100)
        );
        request.source().aggregation(AggregationBuilders
                .terms("starAgg")
                .field("starName")
                .size(100)
        );
    }




    private void buildBasicQuery(RequestParams params, SearchRequest request) {
        // 1.构建BooleanQuery
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        // 2.关键字搜索
        String key = params.getKey();
        if (key == null || "".equals(key)) {
            boolQuery.must(QueryBuilders.matchAllQuery());
        } else {
            boolQuery.must(QueryBuilders.matchQuery("all", key));


//            request.source().query(QueryBuilders.matchQuery("name",key));
//            HighlightBuilder highlightBuilder = new HighlightBuilder();
//            highlightBuilder.field("name");
//            highlightBuilder.preTags("<em>");
//            highlightBuilder.postTags("</em>");
//            highlightBuilder.requireFieldMatch(false);

        }
        // 3.城市条件
        if (params.getCity() != null && !params.getCity().equals("")) {
            boolQuery.filter(QueryBuilders.termQuery("city", params.getCity()));
//            boolQuery.must(QueryBuilders.matchQuery("city", params.getCity()));
        }
        // 4.品牌条件
        if (params.getBrand() != null && !params.getBrand().equals("")) {
            boolQuery.filter(QueryBuilders.termQuery("brand", params.getBrand()));
//            boolQuery.must(QueryBuilders.matchQuery("brand", params.getBrand()));
        }

        // 5.星级条件
        if (params.getStarName() != null && !params.getStarName().equals("")) {
            boolQuery.filter(QueryBuilders.termQuery("starName", params.getStarName()));
//            boolQuery.must(QueryBuilders.matchQuery("starName", params.getStarName()));
        }
        // 6.价格
        if (params.getMinPrice() != null && params.getMaxPrice() != null) {
            boolQuery.filter(QueryBuilders
                    .rangeQuery("price")
                    .gte(params.getMinPrice())
                    .lte(params.getMaxPrice())
            );
//            boolQuery.must(QueryBuilders
//                    .rangeQuery("price")
//                    .gte(params.getMinPrice())
//                    .lte(params.getMaxPrice())
//            );
        }
        if (params.getSortBy().equals("score")) {
            request.source().sort("score", SortOrder.DESC);
        } else if (params.getSortBy().equals("price")) {
            request.source().sort("price", SortOrder.ASC);
        }

            FunctionScoreQueryBuilder functionScoreQuery =
                    QueryBuilders.functionScoreQuery(
                            // 原始查询，相关性算分的查询
                            boolQuery,
                            // function score的数组
                            new FunctionScoreQueryBuilder.FilterFunctionBuilder[]{
                                    // 其中的一个function score 元素
                                    new FunctionScoreQueryBuilder.FilterFunctionBuilder(
                                            // 过滤条件
                                            QueryBuilders.termQuery("isAD", true),
                                            // 算分函数
                                            ScoreFunctionBuilders.weightFactorFunction(10)
                                    )
                            });
        request.source().query(functionScoreQuery);

//        request.source().highlighter(new HighlightBuilder().field("name").requireFieldMatch(false));
//        request.source().query(QueryBuilders.matchQuery("name",key));
            HighlightBuilder highlightBuilder = new HighlightBuilder();
            highlightBuilder.field("name");
            highlightBuilder.preTags("<em>");
            highlightBuilder.postTags("</em>");
            highlightBuilder.requireFieldMatch(false);
        request.source().highlighter(highlightBuilder);
    }

    public PageResult handleResponse(SearchResponse response) {
        // 获取命中的所有内容
        SearchHits searchHits = response.getHits();
        // 获取命中的总条数
        long total = searchHits.getTotalHits().value;
        System.out.println("命中的条数为: " + total);
        List<HotelDoc> list = new ArrayList<>();
        // 获取命中的文档对象数组
        SearchHit[] hits = searchHits.getHits();
        for (SearchHit hit : hits) {
            // 解析每一个hit对象得到对应的文档数据
            String json = hit.getSourceAsString();
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);

                Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            if (!CollectionUtils.isEmpty(highlightFields)) {
                HighlightField highlightField = highlightFields.get("name");
                String join = StringUtils.join(highlightField.getFragments());
                hotelDoc.setName(join);
            }
            Object[] sortValues = hit.getSortValues();
            if (sortValues.length > 0) {
                Object sortValue = sortValues[0];
                hotelDoc.setDistance(sortValue);
            }
            list.add(hotelDoc);
            System.out.println(hotelDoc);
        }
        return new PageResult(total, list);
    }
}
